The influence of two plasticizers, propylene carbonate and dimethyl sulphoxide, as well as different salt concentrations of Li(TFSI), on properties of a polymer gel electrolyte material has been studied using differential scanning calorimetry (DSC) and ac impedance and FTIR spectroscopy. Variations of glass transition temperature and the conductivity behaviours of the systems were examined, and found to be highly dependent on the amount and type of the plasticizer used. Characteristic band-shifts in FTIR spectra, indicating coordination of lithium ions, have been found for the polymer and both the plasticizers in the corresponding binary solutions. These shifts were used to study the coordination preferences in the complete ternary electrolyte system. The combined results from the three experimental techniques have been discussed.

The base-catalysed 1,3-proton transfer reactions in 1-methylindene have been studied theoretically in polar (water) and unpolar (cyclohexane) solvents, respectively, for two different choices of bases, namely ammonia and trimethylamine (TMA), using the SM

Determination of structural and stereochemical features of reaction intermediates in transition metal catalysed reactions is of central interest. Bispidine derivatives as ligands in (π-allyl)palladium complexes in combination with 1H NMR spectroscopy are shown to be useful tools for revealing structural characteristics of these reaction intermediates. As a support for the conclusions drawn from NMR investigations, X-ray crystallography and calculated structures were used.

Complexes of bispidine derivatives with varying substitution pattern and different pre-formed bis[(η3-allyl)palladium chloride] complexes were formed. The resulting complexes were analysed with 1H NMR spectroscopy, especially regarding the inter-ligand NOEs and the chemical shift effects due to anisotropic effects. It is shown that a large steric interaction between the aromatic systems of N,N'-diphenylated bispidine derivatives and various (π-allyl)palladium systems can be obtained. This steric interaction can be used for hindering rotation around C-C single bonds in (π-allyl)palladium ligands.

Furthermore, the nearness of the aromatic systems and the (π-allyl)palladium ligand give rise to anisotropic effects that, after quantification, can give information about the structure in such complexes. The inter-ligand NOEs can, in the case of a N,N-diphenyl substituted bispidine derivative, be used for assignment of relative configuration in a set of acyclic (π-allyl)palladium ligands. With a bispidine derivative carrying chiral substituents, the inter-ligand NOEs were used for assignment of absolute configuration of (π-allyl)palladium ligands.

In this thesis the use of molecular oxygen and hydrogen peroxide as mild oxidants in transition metal-catalyzed oxidations of organic substrates is discussed. The thesis is divided into three parts.

In the first part the use of heteropolyacids as robust oxygen-activating agents for aerobic reoxidation of zerovalent palladium is described. This aerobic reoxidation system has been applied to two different palladium-catalyzed reactions, the allylic oxidation of cyclohexene and the 1,4-oxidation of conjugated dienes. It was demonstrated that the presence of a benzoquinone, which can act both as an electron-transfer mediator and a coordinating ligand in the intermediate palladium π-allyl complex, is of importance for efficient reactions.

In the second part, studies of systems for mild oxidations of tertiary amines to amine N-oxides are described. It was found that a fully reduced N1,N5- dialkylblocked flavin catalyzes the H2O2 oxidation of tertiary amines, giving the amine N-oxides in good yields in fast reactions. The reduced flavin acts as a precursor of the active catalyst, which is generated in the presence of air. Co(salophen), another investigated potential catalyst, was found to form a 1:2 complex with N-methylmorpholine N-oxide (NMO). This catalyst-product complex may inhibit the amine oxidations.

The final part deals with in situ generation of NMO from N-methylmotpholine (NMM) in the osmium-catalyzed dihydroxylation of olefins. In a model study it was demonstrated that mCPBA in the presence of catalytic amounts of NMM is an efficient reoxidant for osmium(VI) in the dihydroxylation. Further investigations showed that H2O2 is an excellent oxidant in osmium-catalyzed dihydroxylations where NMM and a flavin are employed as cocatalysts. Different cis diols were synthesized in good yields by this procedure.

The transition metal oxide V6O13 is a promising cathode material for high-capacity lithium-polymer batteries in conjunction with a lithium-metal anode. The electro-chemical behaviour of V6O13 has its origin in the ability of the vanadium ions to change their-oxidation states, combined with the open nature of its crystal structure which allows lithium ions to diffuse through it. When incorporated into the cathode, the material passes through a series of lithiated phases as the battery is discharged. Inthis thesis, structure-property relationships of these lithiated phases have been studied. The techniques used have been in situ X-ray powder diffraction and single-crystal X-ray diffraction on electrochemically lithiated samples, in combination with electrochemical cycling.

Five different lithiated phases were identified : LixV6O13 for x = 0.5, 1.0, 2.0, 3.0 and 6.0 at potentials 2.78, 2.68, 2.52, 2.45 and 2.00V vs. Li/Li+, respectively. The structures of the x = 0, 2.0 and 3.0 phases have been investigated using single-crystal techniques; deformation electron density refinement has been performed for the x=0 and 2.0 phases. The reduction (from V5+ to V4+) of one of the threeindependent vanadium atoms (V2) in the asymmetric unit can be identified with some degree of certainty as Li2V6O13 is formed. On this basis, a proposal is made for the complete sequence of vanadium oxidation-state changes for the entire lithium insertion process.

The oxidation behavior of 3-aminosalicylic acid (3-ASA), 4-aminosalicylic acid (4-ASA) and 5-aminosalicyclic acid (5-ASA), the active part of the drugs Sulphasalazine and Dipentum for the treatment of ulcerative colitis, has been compared. The redox beha

The CuO2 compounds LiCuO2 and LiCu2O2 both contain CuO4 squares knit together in linear chains. These chains are all equivalent in LiCuO2 and grouped in pairs in LiCu2O2. From susceptibility measurements the spin interaction in both compounds is seen to be dominated by Heisenberg antiferromagnetic exchange

We have investigated how a neural network representation of intermolecular potential functions can be used to elevate some of the problems commonly encountered during fitting and application of analytical potential functions in computer simulations. For this purpose we applied feed-forward networks of various sizes to reproduce the three-body interaction energies in the system H(2)O-Al(3+)-H(2)O. In this highly polarizable system the three-body interaction terms are necessary for an accurate description of the system, and it proved difficult to fit an analytical function to them. Subsequently we performed Monte Carlo simulations on an Al(3+ )ion dissolved in water and compared the results obtained using the neural network type potential function with those using a conventional analytical potential. The performance and results of our calculations lead to the conclusion that, for suitable systems, the advantages of a neural network type representation of potential functions as a model-independent and "semiautomatic" potential function outweigh the disadvantages in computing speed and lack of interpretability.

Boron Neutron Capture Therapy is a binary cancer treatment modality, involving the delivery of a suitable boron compound to tumour cells followed by irradiation of the tumour by thermal neutrons. Boronated agents can selectively be delivered to tumour cells either directly with tumour-specific boron compounds, or by use of targeting strategies. However, the efficacy of this method would increase if the boron agents are localised in the cell nucleus rather than in the cell cytoplasm when neutron irradiation takes place. With these considerations in mind, some boronated DNA intercalating/interacting agents such as phenantbridine- acridine spermidine and naphthalimide derivatives were synthesised.

Amincalkyl-o-carboranes were synthesised in order to be used both for coupling to macromolecules and also for halogenation of their corresponding nido- derivatives. The amino groups were introduced using the Gabriel reagent N, N-ditenzyl iminodicarboxylate to provide 1-(aminomethyl) and 1-(2-aminoethyl)-o-carboranes.

The first attempt to achieve the possibility to accumulate a higher concentration of boron atoms in the cell nucleus was to synthesise carboranyl phenanthridinium analogues by reacting a p- or o- carboranyl moiety with phenanthridine, a chromophore with a planar aromatic ring system as DNA intercalator.

Boronated acridine-spermidine, boronated diacridine, and boronated dispermidine were obtained in orderto 1) increase water solubility to avoid the interaction of these agents with non-DNA sides of the cell, especially membranes; 2) enhance the feasibility of a higher DNA-binding constant and also decrease the DNA-drug dissociation rate.

Finally, the synthesis of a boronated naphthalimide derivative was carried out by nucleophilic reaction of a primary aminoalkyl-p-carborane with naphthalic anhydride.

Perhydrohistrionicotoxin, 1, is related to a family of alkaloids which display pharmacologically interesting properties. The thesis deals with development of new methods for the chemical synthesis of such alkaloids, and is divided into three parts according to the different approaches.

The first part describes a modification of a previously developed synthesis in which the azaspiro system was formed via an intramolecular ring opening of either an epoxide or an iodonium ion by a nitrogen nucleophile. The alkene precursor of the iodonium ion was synthesised in good overall yield but cyclisation was not accomplished. The epoxide was prepared in good yields but low diastereoselectivity in the epoxidation step rendered this route as a poor alternative.

The second approach describes the use of a [2,3] sigmatropic rearrangement in combination with a ruthenium-catalysed ring-closing metathesis (RCM) for the synthesis of the azaspiro ring systems. The [2,3] rearrangement of an allylic selenide was completely stereospecific and both azaspiro-[4.5] and [5.5] systems were synthesised by RCM. This methodology was utilised in a formal total synthesis of 1 where a known key intermediate was prepared in 10 steps and 20% overall yield starting from 2,3- epoxycyclohexan-1-one. The synthesis is potentially enantioselective as both enantiomers of the starting material are available in high enantiomeric purity. A possible route to 6-epi-1 was identified by the addition of an allyl boron reagent to an oxime.

In the third approach a convergent enantioselective total synthesis of 1 is described. The key step was a Lewis acid-promoted, diastereoselective, intramolecular imino ene-type reaction. A highly efficient one-pot, three-component coupling involving two chiral building blocks was used to synthesise the cyclisation precursor. The configurations of the stereogenic centres in the two building blocks originated from kinetic resolutions via Sharpless asymmetric epoxidation of an allylic alcohol. Thesynthesis proceeded in a total yield of 11% involving 10 laboratory operations starting from 1-bromo-3-((tert-butyldimethylsilyl)oxy)-propane.

With the aim of developing synthetic routes to oligodeoxynucleotides and analogues labelled with the positron-emitting radionuclides 18F and 76Br (half-lives 1.8 and 16.2 h, respectively), a number of compounds containing amine-reactive electrophiles were synthesised and used in preparation of oligodeoxynucleotide derivatives labelled in the 5´-position. Some 76Br-labelled nucleoside derivatives, which might be useful in the preparation of oligodeoxynucleotides containing a 5-[76Br]bromouracil unit, were also synthesised.

The novel compounds 4-([18F]fluoromethyl)phenyl isothiocyanate and N-succinimidyl 4-[76Br]bromobenzoate were prepared in 13-15% and 45-60% isolated radiochemical yields, respectively. The previously reported N-succinimidyl [18F]fluorobenzoate was prepared by a modified procedure. The reactions of these compounds with oligodeoxynucleotides and phosphorothioate oligodeoxynucleotides (6- to 30-mers) modified in the 5´-position with a hexylamine group were investigated. With regard to chemical stability, an aromatic position of the halogen was found superior in the conditions of the oligodeoxynucleotide labelling reaction. Using the 18F- and 76Br-labelled succinimidyl esters, labelled oligodeoxynucleotidesand phosphorothioate oligodeoxynucleotides were obtained in 5-19% isolated radiochemical yield.

The relative rates for interconversion and reprotonation of the ion-pair intermediates are of the same order of magnitude in the piperidine catalyzed 'degenerate' rearrangement of 1,3-dimethylindene, as investigated using H-1 and H-2 NMR spectroscopy by

This thesis covers three projects based on the metal-mediated formation of new chiral centers in the prescence of chiral ligands. The first project, involving (N,N)- ligands, concerns the synthesis of some (C2-symmetric bis(aziridine) ligands and the use of these in the addition of organolithium reagents to N-aryl protected imines leading to enantioselectivities of up to 89%. The reaction conditions have been varied with respect to temperature, organolithium:ligand ratio, organolithium reagent and substrate. Some attempts to gain insight into the mechanism were also made. The second project, with (N,O)-ligands, concerns the use of some analogs to NOBIN (nitrogen-oxygen BINOL) which have been tested in the addition of organozinc reagents to N-diphenylphopshinoyl imines giving enantioselectivities of up to 85%. The effect of deprotonation of the ligand with a base prior to addition of imine and organozinc reagent was also investigated. Some experiments to get insight into the reaction mechanism were made. The structure of possible ligand-substrate-metal complexes were suggested for the chiral intermediates for the first two projects, The third project, involving an (N,P)-ligand, deals with the synthesis and use of a new bidentate aziridinophospine ligand in asymmetric palladium-catalysed allylic alkylations.

Solvent-free solid electrolytes can be formed by dissolving a salt in a polymer matrix (e.g. poly (ethylene oxide), PEO). Such compounds are of interest due to their proposed use as solid electrolytes in new types of electrochemical devices e.g. all solid-state thin-film lithium polymer batteries for the consumer electronics market.

Polymer electrolytes are highly complex materials. The present work has used vibrational spectroscopy in combination with ab initio quantum mechanical calculations to assign vibrational spectra and to study conformational changes in the polymer matrix and the dissolved species.

PEO based polymer electrolytes are often multi-phase systems, which is regarded as a major problem since the cations (lithium ions) are conducted only in the amorphous phase, while the crystalline phases can only serve as salt reservoirs. Therefore liquid model compounds, methyl end-capped oligomers of PEO,known as "glymes", have been used to facilitate both the experimental as well as thecomputational part of the investigation.

In an ideal polymer electrolyte the cations are conducted by means of the segmental motion of the polymer host while the anions are thought to diffuse freely using free space created in the , polymer matrix. The cation-polymer complex formation and cation transport have been modelled and features in the vibrational spectra arising from the formation of local salt-polymer complexes have been explained. The internal flexibility, stable structures and the vibrational spectra of the often used TFSI anion, [(CF3SO2)2N-], and the corresponding acid HTFSI have been investigated.

A chiral stationary phase with a silicone backbone and substituted side chains of (S)-N-1-(1-naphthyl)-4-propyloxybenzamide substitution has been introduced for open tubular column GC and SFC. The stationary phase has a broad temperature working range 20-280 degrees C), and provides highly efficient columns (> 3000 plates/meter). One of the key interactions for selectivity is the pi-pi interaction, but the stationary phase can also be used to separate enantiomers without pi electrons. The phase can be used to separate a broad range of compounds, which is demonstrated by the separation of enantiomeric compounds having aromatic rings, amino acid and terpenic alcohol groups. This stationary phase expands the use of Pirkle phases into the field of open tubular column chromatography.

Radiohalogens are widely used in nuclear medicine, both as tool for diagnostic in vivo imaging and inradionuclide therapy. This study deals with the use of radiohalogens; separation, precursor synthesis, labeling and biological behavior. The focus is on 211At and 124I, the former being a candidate for nuclide therapy and the latter potentially useful for diagnostic imaging and Auger-electron based radiotherapy. For astatine the separation, labeling and some biological behavior is described, and for iodine the latter two.

Astatine was separated from an irradiated bismuth target by dry distillation. A novel cryotrap wasdeveloped for the isolation of astatine and subsequent synthesis of radiolabeled compounds. 5-[211At]astato-2´-deoxyuridine (AUdR) and N-succinimidyl-4-[211At]astatobenzoate (SAB) were synthesized in ~95% respectively ~90% radiochemical yields. The former is incorporated into DNA of proliferating cells and can therefore be used as an endoradiotherapeutic agent. The latter is a conjugate for the astatination of proteins. Human epidermal growth factor (hEGF) was tagged with astatine using three approaches: a) direct labeling of native hEGF, b) conjugation with SAB, and c) direct labeling of an hEGF - 7-(3-aminopropyl)-7,8-dicarba-nido-undecaborate(l-) conjugate. The overall labeling yields were ~3.5% for direct labeling, ~44% for SAB and ~70% for the hEGF-nido-carborane conjugate.

A new route to N-succinimidyl 3- and 4- [124I]iodobenzoate, two reagents for radioiodination of proteins is described affording 90% radiochemical yield. Three radioiodinated analogs of PK11195, 1-(2-chlorophenyl)-N-methyl-N-(l-methylpropyl)isoquinoline-3-carboxyamide, a peripheral-type benrodiazepine receptor antagonist, were synthesized. All three analogs were obtained in >90% radiochemical yield. Synthesis and application of 5-[124I]iodo-2´-deoxyuridine (IUdR) is presented.

The close-dodecaborate anion was evaluated as prosthetic group for radioiodination of macromolecules. Its inertness to in vivo dehalogenation was demonstrated by low thyroidal radioiodine uptake in the rat (0.07% ID/g, 20 h post injection).

Transition metal carbides are important refractory materials used in many thin film applications. In this thesis, several transition metal carbides have been deposited using different chemical vapour deposition (CVD) and evaporation processes. In particular, the phase composition and microstructure of these carbide films have been studied.

Several molybdenum carbides have been synthesised by thermal CVD using gas mixtures of MoCl5/H2/C2H4 and MoCl5/H2/CH2I2. Theoretical calculations have been carried out to compare the stabilities of these carbides. The calculations, as well as the experimental studies, suggest that the γ'-MoC1-x phase is a true binary carbide which can be synthesised without stabilisation of oxygen. Nanocrystalline δ- MoC1-x was deposited using both C2H4 and CH2I2 as carbon precursors. A study of general growth trends suggests that the nanocrystalline growth can be explained by a low surface mobility, caused by strongly adsorbed carbon-containing species.

Films of hexagonal WC have been deposited from a gas mixture of WF6/H2/C3H8 using very low pressures and high gas flows. The influence of substrate material on the film microstructures was studied using two model substrates, Ta and Ni. It was found that factors such as etching and carburisation of the substrate played an important role in the microstructure development. The final microstructure could also be influenced by formation and decomposition of more complex carbide phases.

Epitaxial films of TiC have been deposited by co-evaporation of C60 and Ti at temperatures as low as 250 °C on MgO(100) and 6H-SiC(0001). The technique has also been used to synthesise superlattices of transition metal carbides Tic/VC. The epitaxial growth temperature is much lower than expected, and can be explained by a high surface mobility of C60 and/or fragments of this molecule.

A forest soil survey was performed at 180 sites in the county of Varmland in mid-western Sweden. The survey included field observations, the total composition of the soil, the composition of the exchangeable pool and the soil solution at four depths. The southwestern part of Varmland was affected by soil acidification while no indications of soil acidification were found in the north. Evaluation of the data with principal component analysis (PCA) showed that the dominating variables, giving the same spatial distribution as the atmospheric deposition, were those of the soil solution composition and especially the concentration of total Al, inorganic Al and pH in the B-horizon. The composition of the exchangeable pool was less indicative of acidification. Sampling of soil solution in large surveys is possible by the centrifuge drainage technique.

The structure of NH4Cu7-xS4 has been investigated using X-ray single crystal diffraction at varying temperatures. The room temperature structure is best described as a tetragonal crystalline framework with channels incorporating some of the copper atoms in a disordered, almost amorpjous, manner.

Low capacity adsorbents, based on iminodiacetic acid and a crosslinked agarose, Novarose(TM), have been synthesised for the enrichment of metal ions. Test ions Cu2+ with high, and Cd2+ with a moderate affinity for the sorbent were selected. The study includes the effect of specific capacity and matrix composition on the rate of uptake and recovery of these ions. Using a column packed with 0.25 ml of a sorbent and a sample volume of 100 ml, Cu2+ is quantitatively accumulated from all of the matrices studied even at a capacity of 6 mu mol ml(-1) of adsorbent and a flow rate as high as 100 ml min(-1). The enrichment of Cd2+ is affected by the matrix and for quantitative recovery the flow rate and capacity must be properly adjusted. In the presence of 0.01 M Ca2+, a specific capacity of 45 mu mol ml(-1) is needed for quantitative retainment and a flow rate of 100 ml min(-1), whereas a capacity of 10 mu mol ml(-1) suffices at 10 ml min(-1). The advantage of low specific capacity on the removal of matrix elements has been demonstrated. A method based on the determination of conditional stability constants of the metal sorbent complex is suggested for predicting the sorbent capacity needed to acquire quantitative recovery and optimal matrix elimination.

The fullerene molecule C60 is known to undergo many different chemical reactions, including intercalation of alkali- and alkaline earth metals. Relatively little is still known about the reaction between transition metals and C60, and the objective of this thesis was therefore-to investigate the chemical interaction between C60 and some group IV-VI transition metals. The method chosen for this purpose was thin film studies employing either co-evaporation of the metal together with C60 in a ultrahigh vacuum (UHV) system or by the reaction of gaseous C60 with a transition metal halide in a chemical vapor deposition (CVD) process. In addition, adsorption studies of some transition metal halides were also performed in UHV.

In situ x-ray photoelectron spectroscopy (XPS) of films obtained by co-evaporating Ti and C60 at approximately 100°C under UHV conditions showed two different reaction pathways depending on the Ti/C60 ratio in the film: (i) Deposition of films with Ti/C60>~3.5 resulted in disruption of the C60 molecule and titanium carbide (TiC) formation. Based on this reaction, it was shown that epitaxial TiC films could be deposited on substrates like MgO or SiC at substrate temperatures as low as 250°C. X-ray diffraction, low energy electron diffraction, and transmission electron microscopy were used to confirm the epitaxial growth behaviour of TiC. Moreover, the feasibility of using this process in the deposition of refractory carbide multilayers was demonstrated by growing a TiC/VC superlattice. (ii) For Ti/C60<~3.5, a new compound (titanium fulleride, TixC60) was formed. Soft x-ray spectroscopy and Raman spectroscopy also supported compound formation. This TixC60 phase showed enhanced electrical conductivity and optical reflectivity compared to pure C60. Detailed information of the physical properties was impeded by the rapid oxidation upon air exposure. Finally, C60 surfaces showed no adsorption of transition metal halides such as Ticl4 and WF6 and it was shown that this property can be used for selective CVD.

Copper has in its heavier chalcogenides often a high mobility in the solid state. This behaviour has also be found for some ternary compounds where copper appears to govern the observed phase transitions and structural transformations. The focus of this thesis has been to investigate and characterise these transformations with the aim of relating the changes in structure to changes in physical properties.

The thesis is divided into three parts. The first is a summary of the synthesis and characterisation of the compounds while the second relates to the structure refinement. The topic of non-ideal crystal behaviour is outlined by introducing disorder and incommensurate ordering. The third part describes the investigated structures and the various transformations observed for these compounds with a particular emphasis on copper deficient ACu7S4, (A = NH4+, TI+, K+, Rb+). The thermal and resistivity characteristics are linked to the behaviour of copper. A possible explanation for the observed differences between the sulphide and selenide analogues are also introduced.

A method for the preparation of stable reversed-phase columns for high temperature open tubular column liquid chromatography (HT-OT-LC) has been developed and the effect of covalent bonding of the stationary phase to a covalently bonded deactivation laye

PURPOSE: To study the uptake, toxicity and radiation effects in vitro of a diol-amino acid-carborane (DAAC-1) and make comparisons with the previously studied diol-amine-carborane (DAC-1). MATERIALS AND METHODS: Toxicity and radiation effects were studied with clonogenic survival, uptake by measuring the cellular boron content and the subcellular distribution was investigated after organelle separation with centrifugation. The studied cell line was human glioma U343. RESULTS: DAAC-1 showed an accumulation of 1-1.5 times, compared with the culture medium, and was non-toxic up to 47 microg boron/ml. The accumulation of DAC-1 was about 90 times, but toxic effects were detectable already at the concentration 5 microg boron/ml. None of the compounds was localized in the cell nucleus. Following irradiation with thermal neutrons, DAC-1 was about 2.5 times more effective than DAAC-1 and about 4.9 times more effective than neutrons alone, at the survival level 0.2. The dose modifying factors, when compared with the neutron beam alone, were for both DAAC-1 and DAC-1 about 1.5 and about 5 when compared with 60Co-gamma-radiation. CONCLUSIONS: DAAC-1 was less toxic than DAC-1 but gave less accumulation of boron. Both substances gave significant boron-dependent cell inactivation when the test cells were exposed to thermal neutrons.

Lasalocid, which has high affinity for porous graphitic carbon (PGC), has been dynamically adsorbed onto PGC and used in capillary liquid chromatography. Several enantiomers of amines, acids, amino acids and alcohols have been separated on this system an

Uncharged chemically modified cellulose derivatives were mobilized in electric fields through the adsorption of charged and hydrophobic surfactant molecules. The steep and sudden onset in electrophoretic mobility was characteristic of a cooperative bindi

A capillary column switching system was developed for the determination of low, unbound concentrations of the basic drug tolterodine and its active 5-hydroxymethyl (5-HM) metabolite in human plasma. Free concentrations of tolterodine and 5-HM at pM and n

WO3 and WC are two compounds that are widely used for a number of different thin film applications. In this thesis, these compounds have been deposited using two different deposition methods: atomic layer epitaxy (ALE) and chemical vapor deposition (CVD). In particular, the chemical interactions between the precursors and the substrates have been studied.

The etching and adsorption. behaviors in ALE of WO3 were studied for three different metal precursors: WF6, in situ generated subfluorides (WFx) and in situ generatedoxyfluorides (WOxFy). The result suggests that WOxFy can be used as precursors in ALE whereas the other compounds are unsuitable due to etching and/or adsorption problems.

Thin films of WO3 were also deposited by CVD using WF6 and H2O as reactants. It was found that epitaxial WO3 films could easily be deposited on sapphire substrates at temperatures down to 200 °C with this method. Moreover, at a higher total pressure, it was possible to synthesize nanocrystalline WO3 particles by homogenous gas phase nucleation. By collecting the particles on a substrate, porous films could be deposited with a very large surface area. The influence of experimental conditions on the particle size distribution was studied.

CVD was also used to deposit thin tungsten carbide films. By using a C3H8/WF6/H2 precursor mixture, single phase, hexagonal WC could be deposited. It was found that a low pressure and a high linear gas flow velocity increased the zone for WC deposition. The influence of the substrate material was also studied. It was found that the reactivity of the substrate materials was an important factor during the initial stages of growth. Finally, depositions on SiC showed that WC is a potential candidate for metallization of high-temperature semiconductors.

To achieve effective and reproducible extractions of the antioxidant Irganox 1076 from linear low density polyethylene (LLDPE) components at reduced time and cost, the accelerated solvent extraction (ASE) technique was evaluated with solvent composition

Phosphorus has been identified as one of the most important elements in eutrophication of lakes. and the bulk of phosphorus compounds stored in lake sediment contribute to a large extent to this process. It is therefore of great interest to get an adequa